Zilla Gordon* says there has been a research breakthrough that could help diagnosis of potentially life-threatening shellfish allergy.
New research into seafood has pinpointed one of the proteins responsible for the body’s reaction to shellfish, and more specifically can isolate whether an allergy is to crustaceans or molluscs.
Someone diagnosed with a shellfish allergy has to avoid all varieties of the aquatic creatures, but the breakthrough means sufferers could further isolate their intolerance.
A new study from James Cook University and QIMR Berghofer Medical Research Institute has identified one of the proteins responsible for allergies in shellfish.
Tropomyosin is a protein found in the muscle tissue of molluscs – such as abalone, oysters and octopus – but not in crustaceans.
QIMR Berghofer associate professor Severine Navarro said allergen testing meant people were “falling through the cracks”.
An allergy to shellfish is diagnosed with a skin test, exposing the patient to prawns, but a protein found in molluscs can also cause a separate reaction.
Dr Navarro said the test is often inaccurate.
“Patients may show up as negative to shellfish allergy in testing when they actually are allergic, just to a different species,” she said.
Crustacean vs molluscs
The head of JCU’s molecular allergy research laboratory, Professor Andreas Lopata, says allergy to prawns is fairly widespread.
“Allergy to molluscs is not uncommon, but it can be independent to shrimps,” Dr Lopata said.
Dr Lopata said some people could also test positive to both types of seafood.
“While both of them are some type of food allergy, an allergy to crustacean seems to be different to an allergy to abalone and muscles.”
Dr Lopata said future testing, which would encompass seafood, crustacean and mollusc exposure, would mean sufferers could pinpoint their trigger foods.
“A specific diagnosis will enable people to eat certain types of seafood but avoid the ones that are causing their allergy,” he said.
“[It] might be a shrimp, it might be an oyster, or it might be a mussel.”
Future of testing
Dr Lopata said the protein chain of an oyster was different to that of an octopus, meaning tests could be trialled for each animal.
“It will enable us to develop much better tests,” he said.
The next step would be to provide the proteins to diagnostic companies so sufferers can identify which types of molluscs and crustaceans are on the menu.
*Zilla Gordon is a reporter for ABC North Queensland in Townsville. She can be contacted on Twitter at @ZillaGordon.
This article first appeared at abc.net.au.
